The photoconversion efficiency of semiconductor photocatalysts is severely hindered by uncontrolled recombination of photogenerated charge carriers 1-5.Investigating charge transfer dynamics and achieving manipulative...The photoconversion efficiency of semiconductor photocatalysts is severely hindered by uncontrolled recombination of photogenerated charge carriers 1-5.Investigating charge transfer dynamics and achieving manipulative carrier separation is of great interest.展开更多
The TiO 2 nanoparticle thin films have been sensitized in situ with CdS nanoparticles. The SPS measurement showed that large surface state density was present on the TiO 2 nanoparticles and the surface state can be ef...The TiO 2 nanoparticle thin films have been sensitized in situ with CdS nanoparticles. The SPS measurement showed that large surface state density was present on the TiO 2 nanoparticles and the surface state can be efficiently decreased by sensitization as well as selecting suitable heat treatment. Both the photocurrent response and the charge recombination kinetics in TiO 2 thin films were strongly influenced by trapping/detrapping of surface states. The slow photocurrent response of TiO 2 nanoparticulate thin films upon the illumination was attributed to the trap saturation effects. The semiconductor sensitization made the slow photoresponse disappeared and the steadystate photocurrent value increased drastically, which suggested that the sensitization of TiO 2 thin films with CdS could get a better charge separation and provide a simple alternative to minimize the effect of surface state on the photocurrent response.展开更多
Eight new organo polyoxoinetalate charge transfer complexes (DH)\-6X\-2W\-\{18\}O\-\{62\}·(solv)\-n(D=Oxin(8 hydroxyquinoline), Py(Pyridine), Tol(toluene), A(aniline), DMA (N,N dimethyaniline), DEA(N,N diethylani...Eight new organo polyoxoinetalate charge transfer complexes (DH)\-6X\-2W\-\{18\}O\-\{62\}·(solv)\-n(D=Oxin(8 hydroxyquinoline), Py(Pyridine), Tol(toluene), A(aniline), DMA (N,N dimethyaniline), DEA(N,N diethylaniline), X=P, As; solv=DMF, H\-2O) was synthesized and characterized by using elemental analysis, IR, ESR. Polarographly, CV. Conductivity measurement, and X ray circle diffraction. The results showed that the crystal of (H\-2quinH)\-6P\-2W\-\{18\}O\-\{62\}·20H\-2O is Triclinic Crystal System, Space group \%P\{1-\}\%, with \%a=1.4659(5), b=2.045(8), c =2.1153(4) nm, α=90.01(3), β=87.95(2), γ=89.05(3)°, V =6.3393(35) nm\+3. This shows that under the irradiated title compound charge transfer between the organic donor and polyoxometalate anion has taken place.\;Polargraphy and cyclic Voltammetry show that the (H\-2quinH)\-6P\-2W\-\{18\}O\-\{62\}·20H\-2O undergoes three one electron reversible reduction steps in aqueous solution and four one electron quasi reversible reduction in DMF. Room temperature Conductivities of eight the title compounds ranging from 1.2×10\+\{-8\} to 3.6×10\+\{-9\} S·cm\+\{-1\} showed weak semiconducting behaviors.展开更多
Intramolecular charge transfer(ICT) dual fluorescence of p-dimethylamino-benzoylhydrazine(DMABH) in acetonitrile was found to show a highly selective response to HSO - 4 over several other anions. The intensity ratio ...Intramolecular charge transfer(ICT) dual fluorescence of p-dimethylamino-benzoylhydrazine(DMABH) in acetonitrile was found to show a highly selective response to HSO - 4 over several other anions. The intensity ratio of the CT to LE emission and the total fluorescence intensity of DMABH decreased with increasing bisulfate concentration. While the dual fluorescence response was very similar to that of DMABA at a low HSO - 4 concentration, the CT intensity decreased drastically and the LE intensity remained almost constant, however, the difference was observed at a high HSO - 4 concentration, in which both the CT and LE intensities of DMABH decreased. A different recognition mechanism from that of DMABA was suggested for DMABH in which hydrogen bonding and protonization were the recognition interactions at low and high HSO - 4 concentrations, respectively.展开更多
文摘The photoconversion efficiency of semiconductor photocatalysts is severely hindered by uncontrolled recombination of photogenerated charge carriers 1-5.Investigating charge transfer dynamics and achieving manipulative carrier separation is of great interest.
文摘The TiO 2 nanoparticle thin films have been sensitized in situ with CdS nanoparticles. The SPS measurement showed that large surface state density was present on the TiO 2 nanoparticles and the surface state can be efficiently decreased by sensitization as well as selecting suitable heat treatment. Both the photocurrent response and the charge recombination kinetics in TiO 2 thin films were strongly influenced by trapping/detrapping of surface states. The slow photocurrent response of TiO 2 nanoparticulate thin films upon the illumination was attributed to the trap saturation effects. The semiconductor sensitization made the slow photoresponse disappeared and the steadystate photocurrent value increased drastically, which suggested that the sensitization of TiO 2 thin films with CdS could get a better charge separation and provide a simple alternative to minimize the effect of surface state on the photocurrent response.
文摘Eight new organo polyoxoinetalate charge transfer complexes (DH)\-6X\-2W\-\{18\}O\-\{62\}·(solv)\-n(D=Oxin(8 hydroxyquinoline), Py(Pyridine), Tol(toluene), A(aniline), DMA (N,N dimethyaniline), DEA(N,N diethylaniline), X=P, As; solv=DMF, H\-2O) was synthesized and characterized by using elemental analysis, IR, ESR. Polarographly, CV. Conductivity measurement, and X ray circle diffraction. The results showed that the crystal of (H\-2quinH)\-6P\-2W\-\{18\}O\-\{62\}·20H\-2O is Triclinic Crystal System, Space group \%P\{1-\}\%, with \%a=1.4659(5), b=2.045(8), c =2.1153(4) nm, α=90.01(3), β=87.95(2), γ=89.05(3)°, V =6.3393(35) nm\+3. This shows that under the irradiated title compound charge transfer between the organic donor and polyoxometalate anion has taken place.\;Polargraphy and cyclic Voltammetry show that the (H\-2quinH)\-6P\-2W\-\{18\}O\-\{62\}·20H\-2O undergoes three one electron reversible reduction steps in aqueous solution and four one electron quasi reversible reduction in DMF. Room temperature Conductivities of eight the title compounds ranging from 1.2×10\+\{-8\} to 3.6×10\+\{-9\} S·cm\+\{-1\} showed weak semiconducting behaviors.
文摘Intramolecular charge transfer(ICT) dual fluorescence of p-dimethylamino-benzoylhydrazine(DMABH) in acetonitrile was found to show a highly selective response to HSO - 4 over several other anions. The intensity ratio of the CT to LE emission and the total fluorescence intensity of DMABH decreased with increasing bisulfate concentration. While the dual fluorescence response was very similar to that of DMABA at a low HSO - 4 concentration, the CT intensity decreased drastically and the LE intensity remained almost constant, however, the difference was observed at a high HSO - 4 concentration, in which both the CT and LE intensities of DMABH decreased. A different recognition mechanism from that of DMABA was suggested for DMABH in which hydrogen bonding and protonization were the recognition interactions at low and high HSO - 4 concentrations, respectively.